Learn which FSX aircraft have a working FMS or CDU, what the default fleet lacks, and how to fix blank units, route imports and LNAV/VNAV.
Yes, but FSX and FSX: Steam Edition do not provide a universal FMS or fully functional CDU. You need an aircraft add-on or panel built with one. Complex packages such as the PMDG 737 NGX and iFly airliners have integrated systems; some freeware aircraft use simpler, gauge-based FMCs.
Does the default FSX fleet have a working FMC?
No default FSX aircraft has a fully simulated airline-style FMC or MCDU. The Boeing 737-800, Boeing 747-400 and Airbus A321 provide navigation radios, autopilot functions and access to the FSX GPS, but not route, performance and vertical-navigation pages comparable with a real FMS.
The default GPS can follow an FSX flight plan laterally when the autopilot is configured correctly. It does not provide full CDU functions such as cost index, detailed performance calculations, thrust-limit selection or genuine VNAV profile management.
Strictly, the FMS is the complete flight-management system, the FMC is its computing component, and the CDU is the keyboard-and-display interface. Airbus aircraft commonly use the terms FMGC and MCDU. Add-on descriptions often use these names interchangeably.
Which FSX aircraft have an FMS or CDU?
FMS support belongs to the individual add-on package, not the aircraft type. A mistake we see constantly is assuming every downloadable 737 has a working CDU simply because a CDU is visible in the virtual cockpit.
| Aircraft or package | Support level | What to expect |
|---|---|---|
| Default FSX 737-800, 747-400 and A321 | No full FMS | GPS and conventional autopilot navigation, with no operational airline CDU or MCDU. |
| PMDG 737 NGX | Integrated FMC/CDU | Route and performance pages, departures and arrivals, LNAV, VNAV and aircraft-system integration. |
| iFly 737NG and 747-400 FSX packages | Integrated FMC/CDU | Airliner-style route and performance management; exact features depend on the product release. |
| Level-D 767 and similar complex FSX airliners | Integrated FMC | A functional unit tied to the aircraft's navigation, performance and autoflight systems. |
| Selected Airbus add-ons made for FSX | MCDU/FMGC simulation | Airbus terminology and operating logic; system depth varies considerably between packages. |
| Freeware aircraft and replacement panels | Varies | Often a pop-up XML gauge with route guidance but less performance and systems integration. |
For the 737 specifically, our assessment of the NGX's simulated systems explains why its CDU, LNAV and VNAV differ fundamentally from those in the default 737.
Do any freeware FSX aircraft have an FMS?
Some freeware aircraft and panel upgrades include an FMS-style gauge, although they are rarely as deeply integrated as a complex commercial add-on. Our Challenger 300 package with custom navigation gauges notes HoneywellFMC enhancement, while the Fokker 60 panel with selectable INS or FMS equipment demonstrates another approach.
Read each package's documentation carefully. The navigation gauge may be a separate dependency, may appear only as a 2D pop-up, or may require additional files supplied with the panel. A three-dimensional CDU model with no clickable keys is only cockpit decoration.
How do you use a CDU in FSX?
The normal sequence is to power the aircraft, initialise its position, build and validate the route, enter performance data, and then engage the appropriate autoflight modes.
- Confirm that the aircraft actually simulates an FMS. Look for documented FMC, CDU, MCDU, LNAV or VNAV functions rather than relying on cockpit appearance.
- Supply electrical power. Depending on the add-on, this means battery plus external power, an APU or running generators. Some simplified gauges also require the Avionics Master switch.
- Initialise the navigation system. Complex aircraft may require IRS alignment and a position entry before the route pages become usable.
- Enter and check the route. Add the origin, destination, departure, arrival and en-route waypoints. Remove genuine route discontinuities, but do not delete one blindly where vectors are expected.
- Complete the performance pages. Enter the required weights, reserves, cruise altitude and take-off data supported by that particular aircraft. Our step-by-step Boeing FMC entry flow covers the sequence used by compatible 737 add-ons.
- Execute the route and configure the autopilot. Set the flight directors and mode-control-panel altitude, then arm or engage LNAV and VNAV when their conditions are satisfied. An FMS calculates guidance; it does not fly the aircraft unless the relevant autopilot modes are active.
Why is the CDU blank or not following the route?
A blank or unresponsive CDU usually means the aircraft lacks the required gauge, has no electrical power, or is using an incompatible module.
- No simulated unit: The cockpit may contain a static CDU texture or model without any underlying gauge.
- Aircraft not powered: Check the battery, external power or APU, generators and avionics switches required by the add-on.
- Missing or blocked gauge: Reinstall the package using its supplied installer or documented folder structure. Approve only gauge modules that came from a package you intentionally installed.
- Steam Edition incompatibility: Older boxed-FSX installers and compiled gauges may need a Steam-compatible update. Do not assume that every add-on labelled FSX works unchanged in FSX: Steam Edition.
- Route not activated: Check for an unexecuted route, a discontinuity on the LEGS page, an incorrect active waypoint or autopilot modes that were never armed.
- Navigation-data mismatch: The add-on's FMS database can differ from the FSX GPS and scenery database. Missing waypoints, renamed procedures and conflicting runway data are common symptoms.
Can an FSX flight plan be loaded into an FMC?
Sometimes. Some add-ons can import an FSX .PLN file, while others use their own route format or require manual entry. Import support is determined by the aircraft, not by FSX itself.
After importing, verify every waypoint and select the departure and arrival inside the FMS where required. An imported plan may omit procedures, contain waypoints absent from the FMS database, or disagree with the runway and procedure data used by the add-on.